(tumblers tumbling)
I've done some pretty long tumbles before, but never this long. I'm really excited
to open these, but first, we need to go back to the beginning.
At the time you're watching this, it'll be one year in the past. Today is January 1st
2021, and you won't see this until at least January 1st, 2022
So I've always wondered what would happen if you put rocks in a barrel with some grit
and water and just left them alone for a really long time
so that's what I'm going to do today, and I've chosen to use carnelians, these are
from Morocco, and Bahia agates from Brazil
and I chose these rocks because they're pretty nicely rounded rocks
they're nodules, they're not crushed rocks like a lot of rocks you tumble are
so they're going to have a fighting chance of coming out nice at the end of this
because they're - they don't need a lot of grinding
I tried to match up the rocks in both of them as closely as I can, so I've got the
same number of carnelians for each barrel, and the same number of Bahia agates
the sizes are similar, so I tried to match up - you know, as I went through I
paired them up, and I tried to make sure they all matched up.
Some of these have broken edges, but it's a nice smooth break. Over here I've got
some broken edges
so each barrel will have almost the same stuff in it
I'm going to put the same amount of water, I'm going to use a little more water than
normal, just because I'm afraid that it's just going to dry out over the course of
a year, as rock dust accumulates in there it tends to make the slurry thicker and
thicker, and I don't want it to get too thick.
I'm going to put the same number of - or same amount of grit in each of them,
I'm going to use four tablespoons in each barrel.
The difference though is going to be, this one is going to have silicon carbide grit,
and this one is going to have aluminum oxide grit. The size of the grit over here
will be 60/90, and the stuff over here will be 80 grit. So those are
approximately the same size grits.
Silicon carbide grit, as it breaks down, as the rocks roll and it gets crushed in
between the rocks, it's very brittle and it breaks into little pieces, and those
little pieces are sharp, because they're broken. So silicon carbide's really good
for grinding rock and wearing rock away, so it's good usually in the first part of a
tumble, so I use that in the first couple stages of most of my tumbles.
Aluminum oxide, on the other hand, when it gets worn down, it wears down and the
pieces get smaller and smaller and smaller but kind of rounded
so they don't break, they wear down. That makes it good for polishing, and I usually
use it at the end, the polish that I use in my tumblers in aluminum oxide, and
the 500 grit I use is aluminum oxide, because I'm kind of getting ready for
the polish stage
so the only difference will be silicon carbide here, aluminum oxide here
rocks almost the same, same amount of water, same amount of grit
and so we're going to see what happens so let's get these in the barrel and
put them on the tumbler!
(tumbler rumbling)
Now I just have to find something to do while I wait!
♪ (upbeat music) ♪
Well I suppose before I open these up I ought to make some predictions about
what's going on inside
To be honest I have no idea, but I'm going to take a couple guesses and just
kinda tell you what's going on in my head
Before I do that though, I want to show you the bottoms, both of them are kind
of indented, kind of sucked in probably about an inch
both look about the same, my barrels don't usually do that, but I didn't put anything
different in as far as like, I didn't put hot water in
if I would've put hot water in I could see that happening
but I put cold tap water like I usually do
these both started out 1,640 grams and they both lost 4 grams over the
course of the year
so I don't know where that extra weight went, but maybe it's rubber worn off
the outside of the barrel or something, I don't really know
so
before I started this I would've said
within a week probably the grits are going to be broken down to the point
where they're not doing any major grinding anymore, that why I change the grit after
a week in the tumbler usually
because it's just broken down, and it's pretty ineffective at that point
however, in listening to these, they sound different
listen to this one, this is the silicon carbide
(rocks rattling gently)
it sounds like there's a lot of liquid and a few little rocks in there
this one, the aluminum oxide one, sounds completely different
(rocks rattling more heavily)
that sounds like a lot of rocks
so I think these got worn down more
even though I haven't changed the grit, I mean I really haven't opened
these up at all, so I'm thinking there's going to be smaller rocks in here
and bigger rocks in here, just based on the sound, I would not have said that
before I took these off the tumbler, and these really have been on the tumbler,
I haven't touched them in a year, I haven't taken them off and opened up the lids
and peeked at all, they've been just rolling for a whole year
so uh,
the other difference is, like I said before aluminum oxide is better at polishing,
I would expect these to be shinier, if one's shinier than the other I'd bet on this one
although silicon carbide broken down into really really small pieces, maybe that'll
polish also, so I really don't know what to expect there
so anyhow, let's go open them up and see what's inside
is it weird that I'm nervous right now?
it's only been a year
can't get the lid off, it's sucked right on there, there we go
(laughs) that is really really thick, holy cow
well, they're not gone.
This is the silicon carbide
so let me get that rinsed off, there's some stuck in there
wow, that is some thick thick grit
or slurry I should say
alright, this is the aluminum oxide barrel
I will be showing you these closer in a little bit, and I'm going to weigh the
rocks and see how much they change and all kinds of stuff, but
here goes
still thick, I don't know if it's quite as thick as the other one
Well I got them all washed off and dried and look who showed up, Nancy came down
from upstairs to see what I was doing down here
Well, a couple reasons, you know I'm an old science teacher, so I like a good experiment
and secondly, I've been hearing about these rocks for like a whole year, so
even I was impatient to find out what they looked like today, so
and I couldn't be happier, this is just so exciting, it started out as a little stunt
and turned out really cool. Really good demonstration of the difference
between silicon carbide and aluminum oxide, so
I don't know if you can tell, but these piles of rocks are smaller than these
piles of rocks
these lost about 27% of their volume by weight, and these only lost about 7%
these didn't shine up, and these got very shiny, so big big difference
Yeah, the shine is just clearly different
these are - definitely got a nice glare, these are dull looking
pretty but dull
yeah
kind of like me (laughs)
yup!
anywho, these are
these are the carnelians up here, and I didn't understand this about this type
of carnelian but
I just got done tumbling some by my regular methods, and the carnelian, the orange
part is just around the outside, it's just a thin layer, and then it's all white
quartz on the inside
so these are all - I just tumbled all the orange right off of them
so this used to be orange like those?
yup
so it just tumbled all of that off of there
these are all full of pits, those got smoothed out, so that's why
you use this in the first stage, and then the aluminum oxide later on the polishing
stage
these are the Bahia agates, oh, I wanted to show you one other one
this one
is all hollow inside, I've got just a drill bit here
and this, you can just move it all around in here, that's all completely
hollow, it goes in about 3/4's of an inch or so, and it's big, I can move it all around, so
that's all - it was a pain in the butt, I had to keep filling this with water,
dumping it out, filling it and dumping it
but uh,
got it all clean! yeah that is weird
this one's really neat. This has little eyes all over it, just
(Nancy) That one caught my attention right away when I walked down.
(Rob) You've got eyes and stripes, just
just a cool rock. What more could you want?
I don't know! Except shine, like those.
Well, that. This one's really cool too, got some nice
bands on it.
So, anyhow! These turned out really really interesting
So you tumbled them for a year, I heard you doing some math calculations
tell me a little bit about that.
So I figured out if the tumbler barrel was rolling, like along the ground
for as long as it rolled in there, it would go 4,984 miles
and so then I got on a map and I'm trying to figure out what's that far away
Hawai'i was too close, it's about 500 miles too close
Thomas from 99 Rockhounding, I was chatting back and forth with him, and he
was helping me out, and he figured out that Timbuktu was almost exactly 4,984 miles from
Alpena, Michigan
So, you know it can't roll across the water but if it could, that's how far the barrel
would've rolled. As the crow flies
Yes.
As the barrel flies? Anyhow. Eh, whatever.
It went, it would go that far, so. Did a lot of rolling to get here!
So, I don't think I'm going to trade in my old methods for this, but this was
a very fun little experiment.
If you'd like to see some more of my videos, if you're new here, I put together a
playlist of some of my favorites, so go check those out and I'll see you over there!